Hair advice? i am super freaking out!!?

ok so i just found a white hair. im lyk 13! andd i flat iron my hair about everyother day. duz flat ironing cause white hairs or is this stresss or both? sorry i like love my hair cuhz its lyk long and stuff but IT CANT BE WHITE. aha thanks (= helps muchhh appreciateded lyk yu dont even kno